


Bad Input

by technofantasia



Category: Rise of the Teenage Mutant Ninja Turtles (Cartoon 2018)
Genre: Angst, Denial, Gen, Psychology
Language: English
Status: Completed
Published: 2020-09-09
Updated: 2020-09-09
Packaged: 2021-03-07 01:14:21
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 2,317
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26378635
Author URL: https://archiveofourown.org/users/technofantasia/pseuds/technofantasia
Summary: He remembers something Donnie said to him once.(Sometimes, the truth really is too much for one guy to handle)
Comments: 10
Kudos: 100





	Bad Input

**Author's Note:**

> look okay i just wanted to write some sads so that is what this is

He remembers something Donnie said to him once.

It had been a Tuesday—the most unremarkable day of the week, not that a bunch of teenage turtles living in the sewers would care about that, having no school or job or daytime responsibilities to speak of that would make a Tuesday any different from any other day. There were just some parts of human culture they would never be able to understand.

In fact, that's the reason he remembers it was a Tuesday that particular day; he and Donnie were talking about the weirdness of the concept of Tuesdays.

"…But, that's what I'm saying!" He remembers exclaiming, popsicle sticking out of his mouth. It was summer, then, and a hot one at that; just earlier that day, Mikey had tried to fry an egg on the sidewalk topside and almost succeeded. He just couldn't get the egg white unstuck from the concrete. The gloopy mess was completely adhered to the ground; in hindsight, it wasn't a great idea. Looked disgusting. "People always talk about how time moves slower on Tuesdays, right? Maybe it actually _is_ some kind of, like, special magic day or something! Who knows? Other magic exists, right?"

Donnie had been working on his own popsicle, held up awkwardly between his teeth as he lounged sideways over the arms of the recliner—grape flavor, even though he honestly never even liked grape flavor all that much. Let it never be said Donnie didn't go all out for the aesthetic. His own popsicle was cherry flavor, signature color be damned; blue raspberry just never did it for him. 

" _Please_ , don't you _dare_ try to bring magic into this. Tuesdays belong entirely to the realm of science! And for that matter, time doesn't just suddenly decide to move _slower_ because of an arbitrary calendar system used to judge the arbitrary workings of an arbitrary society," he said, gesturing with his popsicle to an invisible audience. "Sure, your personal experience of time can change if you're moving fast enough according to Einstein's theory of relativity, but you'd never be able to actually _notice_ the difference unless you were moving at near lightspeed!"

"Then how do you explain Raph's safety lectures taking literally forever?"

Donnie paused in his rant. "…Okay, that's something else," he said, rolling his eyes. "That isn't time slowing down, it's your _perception_ of time slowing down. You know, like… in your brain."

He turned his head to the side so he could look his brother in the face, flipped upside down over the chair as he was. "So, your brain thinks boring stuff takes longer…? How does that work?"

"Oh, it's actually pretty simple!"

Perhaps predictably, his amazing brother then proceeded to launch into a long, detailed explanation he never had any hope of being able to follow, let alone remember.

"…Okay, I can see your eyes glazing over," he'd said after a while, his eyebrows furrowed in slight annoyance. Took him long enough. "I'll give you the tl;dr."

" _Please._ "

"Basically, the brain is really good at tricking you into seeing what it wants you to see and feeling what it wants you to feel. Oftentimes, it doesn't matter what's actually happening in front of you; your brain will just decide what it thinks _should_ be happening, and then that's what you end up experiencing."

That made him nearly startle off the chair, falling down onto Donnie's plastron and forcing his neck at an awkward angle. He flipped himself around so he was lying mostly on top of his brother.

"What?! No way!" he sputtered. "So, everyone's brain is like… their own personal matrix, or something?Is anything even real? Are you real? Am _I_ real?!"

"What? No! Or… yes? Yes, we're both real, but no to the matrix thing. Well… kind of. It isn't anything to get so shocked about, anyway." Donnie nudged him a little to get him into a more comfortable position. They were both kind of sticky with sweat at that point, but the casual affection was still nice. "It's not like the version of reality I'm seeing is _that_ much different from the one you are, as much as I wonder about that sometimes— _ow_."

Talk shit, get hit.

After rubbing at his now slightly sore cheek, he continued. "If we both saw something, then we watched a recording of that moment picked up by a camera, we'd both remember pretty much exactly what the recording showed, albeit with less detail. However, if it needs to, your brain can kind of… tweak the moment, just a little bit. It can get some things to take more of your attention, or ignore other things that don't seem important. That's where the time dilation comes in; boring stuff takes a lot of attention and feels like it should take more time, so it does. Sometimes your brain can even outright reject information it doesn't like, or create information that seems like it should be true! Pretty cool, right?"

"Uh, I guess? But it's kind of wild to think that your brain can just lie to you and make you believe it without you even noticing. Stuff like that can be kind of scary, yaknow. To other people."

Donnie scoffed. "Your brain doesn't _lie_ to you! That would be dumb. It just… stretches the truth a little, sometimes. Either way, that's the only way you've ever seen the world, so it's not like knowing changes anything. Nothing to have an existential crisis over."

"I said _other people_ would find it scary, gosh! I'm cool as a cucumber over here. No existential crisis in sight!"

"Suuuuuure."

He huffed and looked up at the skylight far above them, uncharacteristically lost in thought. Maybe it was just the heat getting to him but the topic _was_ weirdly upsetting him. "Whatever, it's just… what's the point of your brain making up stuff anyway? Why is it so random? It seems like living in the moment would be better _and_ easier."

"It's not _random_. Nothing in science is random! It only makes stuff up, as you put it, when it really needs to. The brain is one of the most advanced machines ever made; everything it does is for the express purpose of keeping the organism it belongs to alive and functioning. Sometimes, the organism just can't handle the whole truth, for whatever reason. When that happens, it edits the input just enough to keep everything running smoothly. No sense in having a machine read bad input."

There was silence for a while after that. Donnie's finished popsicle stick dropped to the ground idly.

"What? Did I say something weird?" He said after a moment, slightly confused.

"No, no, just… that's kind of freaky, D. People aren't computers. How can you give a _person_ bad input?"

"I don't know, by telling them something they don't want to hear? Showing them something that conflicts with their previously held worldview? Actually, that ties into some really interesting stuff about the theory of cognitive dissonance! You see, when—"

Fearing another trademark Donnie rant he'd have to tune out (and not really wanting to stay on this topic of conversation longer), he decided to slam on the brakes. "You know what? Forget I asked. What does any of that have to do with Tuesdays?"

Donnie huffed and pouted a little at getting interrupted, but rolled his eyes and accepted the change in topic.

"Tuesdays go slower for most humans because it's the middle of the work week; there's no change from the day before and there's nothing to look forward to the day after, so the brain edits it to seem slower. It isn't _actually_ going slower, and so really shouldn't have the same effect on us! We _never_ do anything different, no matter what day of the week it is. If you feel a difference, you must just be expecting it to feel different because the media says it should."

"Jeez, why didn't you just say that in the first place and save me from all that existential mumbo jumbo?"

"I told you not to get existential about it!!"

All in all, it was a pretty normal, slow, unremarkable Tuesday. Nothing noteworthy about it at all.

And yet, somehow, he finds himself remembering it, remembering that conversation, that sentence that stuck with him for whatever reason even though the day itself had faded from sharp memory into a mere fuzzy recollection of summer bliss. At the time, it had seemed in his gut an important thing to remember, so remember he did; he's always been good with intuitive stuff like that. Ha.

"No sense in having a machine read bad input," Donnie had said. Back then, he didn't really understand what that meant; he was able to parse the words just fine, sure, but he was never able to think of people like computers in the same way his brother always does.

…Did.

A sharp wave of agony pulses through him at the wayward thought, bringing fresh tears to his eyes, bottoming out his stomach, making his very soul feel weak and unable to hold weight. He gulps in a pained breath and tries to stay firm, though, out of nothing less than necessity; he _needs_ to bear that weight, the too-heavy weight on his lap, slumped against his frantically beating chest, heavy and unmoving, _de-_

Another wave hits him before he can complete the thought.

In some part of his mind, detached from the reality he wants no part of, Leo thinks he understands now what his brother had meant with that phrase, "bad input". It's a programming term, he thinks he remembers from countless days and nights spent next to his beloved techie brother tapping at his laptop; input that can't be handled by the program. Input that shouldn't exist.

The brain rejects information it can't handle. To keep the organism running smoothly. Bad input.

The slick, sticky feeling of warm liquid against his skin. The way it shimmers in the light as it continues to pulse and flow through the grooves in the concrete, reflecting the light of the moon like an ocean of cherry syrup. The smell of it, sharp and overwhelming and _wrong wrong wrong too much far too much_. The knowledge of where it came from, locked somewhere in his overworked mind, in some deductive process that hasn't finished yet.

Bad input.

His brother, his Donnie, Donatello, whose face looks to him like a thousand different moments of "fuck off" and "I love you" and razzing that neither of them ever meant when it came down to the wire, of tag and soft smiles shared after nightmares and sweat and grape popsicles, D, Don, who he thinks of even now and can only get back a kneejerk feeling of _love love keep safe good love_ , who just hours ago was characteristically putting too much thought into which battleshell to wear for the day even though it never really mattered, who is in his arms right now, heavier than he's ever been for some reason judging by how much his arms are shaking, and he still can't quite figure out why.

Bad input.

Where is he right now? Where is this? How'd he get here, anyway? How long has he been here? What happened? Why does he feel so sick?

Bad input.

Sometimes, he thinks, the whole truth really is too much for one guy to handle. He can feel himself try to touch it, can feel the answers to all his questions on the tip of his tongue, but when he tries to search for it with all his _champion skills_ and the _intuition_ he always cared so much about…

Bad input.

It's funny, he thinks, that he used to want to know everything. That the concept of being kept in the dark made him feel so uneasy. He was always just _so_ insecure. He thought that, if he just knew everything that was going on always, nothing bad could ever happen; looking back, that's probably why that conversation rattled him so much. If he was only ever seeing what he wanted to see, how would he know that something was wrong before it went off the rails? The idea unsettled him. He just couldn't accept it, so his good ol' brain rejected it. Isn't that ironic? Funny how he's only realizing that now. Funny how he might have had a shot at realizing it back then if he'd just let Donnie finish his explanation like a good brother would, like he never did. Funny how self reflection like this only ever comes up when it's too late to do anything about it. Funny, funny, haha. He is always _so, so funny_.

(But then again, nobody ever called _him_ the funny one. That title always went to—)

There are some things he just isn't ready to know. Not now, not ever. Leo can accept that now. He can be okay with it. He'll go back home from wherever he is and remind Donnie of that old conversation they had forever ago and Leo will tell him that he understands now and he's always just loved spending time together because when was the last time he said that out loud? And then Donnie will say something about finally getting Leo into science and they'll have some back and forth about it and everything will be okay just like it always is.

Everything will be okay.

Everything is…

…

But… if that's true…

Bad input.

…then why…

Bad input.

…does Donnie…

Bad input.

…have a hole…

Bad input.

…in his…

—

Yeah, Leo decides. Brains are pretty weird.

He always thought they were stronger than that, but it's not the first time he's been wrong. Donnie was always the one with the… well, brains, of the family, not him. Never him.

Brains. Ha.

They look pretty weird, too.


End file.
